Alright, men! Let’s start this experiment right!
It’s time to get serious about the little Ruger American 223 carbine. I’ve taken of the scope and remounted it. I’ve done some very brief tests with a variety of old stuff I had lying around. I threw a bipod on up front for extra weight for now. I might consult with Poli - perhaps some lead weights and epoxy? Bah - I’ll worry about that later. Long story short, I’m done monkeying around. It’s time to bag up, shut up and man up - and start shooting.
Just out of curiosity I decided to consult with Johnny. *GENERALLY* speaking…when you shoot similar loads, you can expect similar results. But…there’s exceptions to every rule. Johnny nearly blew his face off here… he went off the book, and he got bit square on the ass. His assumptions were reasonable, I have done the same thing he did many times and never had even a shadow of a problem. The important thing is that he caught it. When he blew the primers out he shut ‘er down and dismantled his test ammo. CHECK YOUR BRASS FREQUENTLY WHEN DEVELOPING LOADS. The reason he got caught was that as you bump up your powder charges you’ll hit a point where you’ll stop seeing velocity increases…but your pressures will start to spike.
Rather than AR Comp powder, I used Varget. Loading data came from the Hogden website, and as expected, my results were right on par with Johnny’s… with the exception that I didn’t see any pressure signs at all.
Hrrrrrrmmmmmm. I tried some new things on the range. I really take my time when firing test loads, but this time I fired six shot groups, as fast as I could accurately get on target. I am shooting at 200m whereas Jonny is at 100 yards. His AR has a 16” barrel, spun for 1:7. Mine is 16”, spun for 1:8. He shot 5 shot groups, mine are 6 shots.
My average velocity was 350~400 FPS below published data. The published data was obtained with a 24” test barrel. They also seated their bullets deeper than I do. Standard deviations were okay - in the 20 FPS range.
Hmmpfpfpfpppffff. 🤨
Fellas…I think we have room to push here a little bit. As we add powder and pick up velocity the groups seem to be tightening a bit. My ol’ beloved .25-06 was like that. You stoked that pig right up to the gills and it was a tack driver. It had no use for pattycake target/practice loads.
😂
I’ve never been able to shoot Berger bullets well. Everyone else can but me. I don’t have a single success story with them in any gun I own. But then again, they piss me off so bad that after a disgraceful session like this, I put them back on the shelf with the intent of giving them away or trading them off. Not this time!
Here’s what we’ll do: starting at 25.5gr of Varget…we’ll start barking up the charge in 0.5gr increments. My goal is to get them moving around 2750 ~ 2850 FPS. We seem to pick up 100 FPS per second per 1 gr. increments. We’ll go up slow because we’re going off the book now. If I see any pressure signs, we’ll shut er down and call it good.
Get your precision tools out and adjust the bullet seating depth a thousandth of an inch at a time. Test the cartridges to make sure they're not actually getting engraved in the bore. A lot of guys have reported dramatic increases in accuracy at some sweet spot, usually just a little shy of hitting the lands.
ReplyDeleteYou’re right.
Delete*Usually* they find their jam length, and seat the bullet approximately 20 thou back from that, then start slowly seating the bullet further out in increments until they find the sweet spot.
When I test loads I start with the bullet. If the bullet flies and the accuracy is good…then I might start tinkering with seating depths, powders, primers and cases. This gun is limited by the AR mag…so I do as Johnny does and just seat them as far out as the mag will allow. Also…you can spend a fortune on components and waste time futzing around with loads. For me…I’m not an F Class shooter. If I get down under 1 MOA… I’m good. I prefer to sling up and shoot from the positions if I can…
I sincerely lament having to sell my .243, but I needed the money at the time. It was one of the first of the inexpensive, plastic stock, great trigger models. They only used the experimental name that one year, too. I had no idea it would become somewhat collectible. All I cared about was that it shot about 1.25" with every brand and bullet weight I fed it. It was not a picky eater.
DeleteNever sell your guns. Go without lunch, instead.
Your much-lower-than-expected velocities match what I saw with my Ruger American.
ReplyDeleteThere are significant differences in the lead-angle between 5.56mm NATO and the .223
My Ruger American is stamped 5.56 on the barrel. Does yours actually say .223 Rem or does it say 5.56?
As background for some of your readers, the two chambers are similar but the 5.56 NATO is primarily used in military semi-auto and full auto rifles. It is possible to rapidly fire 29 rounds and then have the 30th round sitting in the smoking-hot chamber and cooking. THen, when GI Joe pulls the trigger, the hot powder burns more rapidly and generates higher pressures. The gentle lead angle of the 5.56mm NATO is designed to mitigate against disasterous pressure levels.
However, it can result in lower pressures as the cartridge + barrel volume behind the base of the bullet grows more quickly at the very earliest stages of the powder combustion.
BTW, how do you get 25.5 grains of Varget into the case? That is a lot of volume.
Thanks for the clarification Joe. Yep - that little beast is chambered 5.56 just like yours. I leave it to others to sweat the negligible dimensional differences. Both chamberings will fireform to the other and once you reset your sizing dies you should be good... shouldn't ya? It seems to work for me anyways. The NATO round is a little hotter too - so I'm told.
DeleteYep - my velocities are right on par with yours - which is good! But... with my 77 gr practice loads... velocities and charges are right in line with the manual. All guns have their quirks...
I seat my bullets out as far as the magazine will let me and I am out around 20 or 30 thou over the book OAL - so I should have a little extra room but not much. We may be looking at a compressed load here which is fine if we approach it slowly and intelligently. We should be safe with Varget and be able to fill that case right up without blowing our faces off... but ya never know. We will nudge it and see what it does.
Looking back on it I shoulda bought one in 223 Wylde
;)